How to get count of posts from categories in Tailor?

Questions
#1

How i can get the count of posts for every category

[collection blogCategories]
handle = "Blog\Category"

[collection allPosts]
handle = "Blog\Post"
==




<!--Offcanvas sidebar-->
<aside id="sidebar-wrapper" class="custom-scrollbar offcanvas-sidebar">
    <button class="off-canvas-close"><i class="athena-cancel"></i></button>
    <div class="sidebar-inner">
        <div class="sidebar-widget widget-creative-menu">
            <ul>
                {% for category in blogCategories %}
                    <li>
                        <a href="{{ 'display-a-blog-category'|page({ slug: category.slug, id: category.id }) }}">
                            {{ category.title }}<sup>here is post count in category</sup>
                        </a>
                    </li>
                {% endfor %}
            </ul>
        </div>
    </div>
</aside>
#2